When field devices are used in automation technology, occasionally problems arise with communications over the digital field buses. The cause of the problems may lie in the actual network technology, such as electrical interference, faulty cabling or defective devices for example. However, complexity is increasingly becoming a problem too. Many devices from different manufacturers must work together. An entirely new category of faults is arising here as a result of incomplete or incorrect protocol implementations, imprecise specifications and unstable device software. In addition, there is an ever higher risk of configuration errors, for example as a result of duplicate address assignments, temporary network overloading or timing problems.
In the meantime very powerful network analysis devices are available for the development of communications devices which enable easy analysis on all communication levels from the physical layer right through to the application. Since these tools must be connected directly to the field bus, they can only be used in a production system to a limited extent. A personal computer is not suitable for installation in the environment of a process engineering system. In particular the use of commercially available personal computers is not possible in areas where there is a risk of explosion in which compliance with special regulations applicable to the operation of electrical equipment is required. In such circumstances, in particular long-term analyses are at least rendered more difficult.
Moreover, a bus tap is required, which cannot be retrofitted without interruption on most field buses.